OneClickPDF

Straighten Skewed Scanned Documents

Last updated: February 24, 2026

Even the best scanners produce slightly tilted pages — the paper shifts, the lid isn't perfectly closed, or the original was placed at a slight angle. That 1-2° tilt makes your documents look unprofessional and can reduce OCR accuracy by 10-20%. OneClickPDF detects and corrects skew automatically.

The Problem

Your scanned documents have pages that are slightly tilted. The skew is consistent enough to look sloppy but too subtle to fix by eye. You need automatic detection with the option to fine-tune individual pages.

How It Works

1

Upload the skewed scan

Drop your scanned PDF into the Deskew tool. The file processes entirely in your browser.

2

Auto-detect angles

The tool analyzes every page and reports the detected skew angle and confidence score. Most scans have 0.5-3° of tilt.

3

Review and adjust

Thumbnails show a live preview of the correction. If the auto-detection is slightly off on any page, fine-tune with ±0.1° controls.

4

Apply and download

Corrected pages are rasterized at high resolution. Pages with no skew are copied losslessly. Download the straightened document.

Deskew PDF

Automatically straighten tilted or skewed scanned pages.

Try It Free

Frequently Asked Questions

How accurate is the auto-detection?
The projection profile algorithm detects angles to 0.1° precision. It works best on pages with multiple lines of horizontal text. Pages with mostly images or diagonal content may need manual adjustment.
Should I deskew before or after OCR?
Before. Deskewing first significantly improves OCR accuracy because the text recognition engine expects horizontal text lines. Even 1° of skew can reduce OCR quality.
Will deskewing make my file larger?
Corrected pages are rasterized, which may increase file size for text-heavy pages. Use the Compress tool afterward if needed. Pages with 0° skew are copied losslessly with no size change.
Can I process a large batch of scanned pages?
Yes. The tool handles multi-page PDFs of any length. Processing is done page-by-page with a progress indicator.

Straightening scanned documents is the difference between amateur and professional output. Auto-detection handles 95% of cases perfectly — the per-page fine-tuning handles the rest. All without exposing your scanned documents to any server.

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